The invention relates generally to the field of computed tomography (CT) imaging systems, and more particularly to geometries and interconnection configurations for the stationary CT systems in which a single detector or multiple detectors and distributed radiation source elements are fixedly positioned in an imaging system scanner.
Many applications exist for computed tomography imaging systems. Developed over recent decades, such imaging systems provide a powerful tool for imaging internal features of subjects of interest, typically presented as slices and volumes. In general, the systems consist of a source that directs X-ray radiation through the subject of interest onto a detector. As will be appreciated, the source of radiation may be any type of radiation that is able to penetrate the subject of interest. The X-ray source and detector, in traditional systems, are mounted on a rotational gantry and spun at a relatively high rotational rate (e.g., two revolutions per second), although faster and slower speeds are also used. Measurements of the incident X-ray intensity on the detectors are acquired at many locations during rotation and are stored for later analysis and processing. The systems then compute useful reconstructed images by processing the acquired intensity measurements, allowing determination of the location of features of interest within the subject, and reconstruction of useful images.
Typically, current techniques employ an X-ray tube and detector electronics rotating in a large gantry. However, they are limited by the need to rotate the source and detector elements about the subject to obtain a 360-degree scan. Increasing interest exists for CT systems that will not require such rotation, and that may be called “stationary CT systems.” As will be appreciated, a stationary CT system may be composed of a large number of X-ray sources, such as field emitters, which need to be properly sequenced and precisely timed. Also, the precise on and off timing is typically in the microsecond range. Consequently, interfaces using properly balanced transmission lines need to be implemented in order to accomplish such narrow sequencing and synchronizing pulses. In addition, a large volume of wires is required to interconnect a system controller to the X-ray source drive circuits and the other functional blocks of the stationary CT system. The performance of these systems is disadvantageously sensitive to the lengths of the interconnecting wires. In addition, single ended, high impedance digital interconnections employed by these systems are highly susceptible to common mode noise.
There is a need, therefore, for a robust, high noise-immunity system wiring interconnection scheme that is less sensitive to interconnection lengths. In particular, there is a significant need for a design that can lighten interconnections between the system components and enhance communication between sub-functions of the system by reducing control wiring and enhancing timing and synchronization. There is a particular need for systems that can generate high-quality images while reducing the mechanical and electrical problems associated with interconnecting and controlling the plurality of X-ray sources in a full arc of the stationary system.